This invention relates to curable adhesives, a heat recoverable article coated on at least a portion of a surface thereof with said adhesive, and to a method of bonding to a substrate using said adhesive.
The adhesive is particularly useful for bonding to a wide variety of surfaces, including polymeric surfaces having a low surface energy, i.e. a surface energy of less than about 27 dynes/cm, as determined by a measurement of critical surface tension. Such surfaces include, for example, fluoropolymers such as an ethylene-tetrafluoroethylene copolymer or polytetrafluoroethylene. It is well known that it is extremely difficult to bond to such surfaces. In U.S. Pat. No. 4,197,380 to Chao et al a hot melt adhesive capable of bonding to such surfaces is disclosed. The adhesive comprises an ethylene copolymer, a fluoroelastomer and a tackifier in specified proportions. While this adhesive performs satisfactorily in many applications it has been found that under certain demanding conditions greater bond strength and/or sealing performance is desired.